100 years ago, titans suddenly appeared on Earth. Soon, human civilization veered on collapse due to the titans. Humans then built a giant wall to defend themselves. Within the giant walls, humans lived in peace, but, 100 years later, the giant wall is broken.
The spaceship AAB-Gamma is dispatched from FAFC headquarters in Japan to make a landing on the planet Mars and investigate reports of UFOs in the area. As they near the red planet, they encounter a mysterious UFO that coats the ship's hull with unusual spores. Taking one of the specimens back to earth, it soon develops and grows into a giant chicken-lizard-alien monster that tramples Japan.
Earthquakes in central Korea turn out to be the work of Yongary, a prehistoric gasoline-eating reptile that soon goes on a rampage through Seoul.
When strange lights descend on the city of Los Angeles, people are drawn outside like moths to a flame where an extraterrestrial force threatens to swallow the entire human population off the face of the Earth. Now the band of survivors must fight for their lives as the world unravels around them.
Some time after Godzilla's battle with Hedorah, a new threat emerges. Gigan, a cyborg dinosaur from the outer space, confronts Godzilla while trying to invade the Earth.
Dr. Decker returns from Africa after a year, presumed dead. In that year, he discovered a way of growing plants and animals to an enormous size. He brings back a baby chimpanzee to test out his theory. As he has many enemies at home, he decides to use his chimp, 'Konga', to 'get rid of them'. Then Konga grows to gigantic proportions and wreaks havoc all over London!
Marine atomic tests cause changes in the ocean's ecosystem resulting in dangerous blobs of radiation and the resurrection of a dormant dinosaur which threatens London.
In an effort to find an economic means of purifying salt water, a joint U.S.-Japanese military command is set up on an isolated Japanese island where an unusual salt water lake is situated. However, their purifying experiments arouse the prehistoric monster Obaki from hibernation at the lake's bottom, and it proceeds to attack Japan. Although made by a U.S. independent film company, this film was based on a Japanese Toho monster film of 1958, "Daikaiju Varan", from which all of the monster effects scenes and a few incidental dramatic shots were edited into it.
Something has been discovered, and this time, a city is under attack by a fast growing T-Rex.
A giant prehistoric praying mantis, recently freed from the Arctic ice, voraciously preys on American military at the DEW Line and works its way south.
Giants Mollusks are released from the earth by an earthquake and start killing people.
A group of post-apocalyptic survivors, struggle to survive in a world where jungles and forests and primeval wetlands and deserts have obliterated civilization. They staunchly face genetically mutating beasts and mysterious diseases in an attempt to re-establish the human race as masters of Earth.
When army of Gigans tries to invade and destroy the Earth, the only one who can stop them is Godzilla.
A ship runs aground on a mysterious atoll leading to an investigation by insurance representative Kusanagi, who discovers an ancient bead that he gives to his daughter Asagi. Meanwhile, ornithologist Nagamine investigates reports of a new species of large bird named Gyaos. As the Gyaos begin to attack, an ancient guardian with a bond to Asagi emerges.
After a meteorite unleashes a three-headed beast upon Tokyo, Mothra tries to unite with Godzilla and Rodan to battle the extraterrestrial threat.
Humanity finally rids themselves of Godzilla, imprisoning him in an icy tomb in the South Pole. All is peaceful until various monsters emerge to lay waste to Earth's cities. Overwhelmed, humanity is seemingly saved by a race of benevolent aliens known as Xiliens. But not all is what it seems with these bizarre visitors. If humanity wishes to survive, they must reluctantly resurrect their most hated enemy, Godzilla.
Mining engineer Shigeru investigates the disappearance and death of his fellow coworkers when prehistoric nymphs are discovered emerging from the mines. After an attack on the local village, Shigeru heads deeper into the mines only to make a more horrifying discovery in the form a prehistoric flying creature. Soon a second monster appears as the two converge in Fukuoka.
The Japanese government sets up a special task force to fight the giant creatures suddenly appearing across the country. Soon, the squad unexpectedly meets a giant silver humanoid who starts appearing every time a space monster attacks!
When a space probe crash-lands on a far-flung Pacific atoll, the craft's alien stowaways decide to take over their new world one creature at a time. Soon, the parasitic life forms latch onto three indigenous critters -- a squid, a crab and a snapping turtle -- and transform them into colossal mutant monsters.
The heat of a meteor crashing into the lake incubates a prehistoric egg, which grows into a plesiosaur-like monster that terrifies the community.